Selecting CNC Machinery

Choosing a machine to best suit your operation. January 28, 2004

I am starting to meet with various CNC salesmen. This will be my first CNC router purchase. What are the most important points in selecting a CNC router?

Forum Responses
(CNC Forum)
From contributor J:
Here are a few (not in order).

Regarding the machine:

What are you planning to do, as in: frame vs. frameless, higher production vs. more custom capabilities, nested base or not (if not, what are the bed consumables: vacuum cups/pods and how costly to replace)?

What machinery is currently in place? What machines would either complement or become obsolete with a new router in place?

What experience, if any, do you have with CNC in general? Can you perform any routine setup/maintenance/troubleshooting without paying for factory support?

What control is being offered? Is it, or can it, communicate directly with the PC CAD/CAM station you will be buying?

With regard to salesmen:

Where do the machine and controller originate (country)? Will your support requirements be served directly by the factory, or through a secondary sales entity?

How complete is their quote? Does it include equipment to match the machine's voltage requirements to your shop? Does it include any tooling? Vacuum pump? Software (one of the most important considerations, if increased productivity is what you're looking for). Gang drill? Delivery and rigging?

I wish you luck on your selection, but I would say this: listen to the salesman when he tells you the price (this is something he actually knows about), but only trust your own research as to the realistic capabilities of the machine, and the real differences between the brands. Visit shops in your area to see what their experience has been with a particular brand. Read every post in forums like this. We have already been through it.

From contributor C:
I agree with the above points of consideration regarding machines. I chose Busellato and am thrilled with its performance, reliability and most of all, support from Delmac. Before you get a machine in there, you had best talk to some software people. Depending on your application, you really need a smooth transition from design to machine code generation. Remember, CNC machines do what they are told! It's getting that information to them that is most important. I know too many people who don't use their machines to their fullest because they did not get their software in order.

From contributor D:
One of the challenges that we faced with this process was knowing the right questions to ask.

You will do yourself a disservice if you take the word of the salesmen on anything. The salesmen is typically trying to spin every comment one direction, and it isn't exactly impartial.

One thing I think you must remember is that nobody's machine will install without problems every time. Maybe it happens occasionally, but with a machine as complex as a CNC router, expect the first month to be filled with hiccups as you work out the kinks. The key is to buy a machine that has the support to keep you moving forward. Local support is always better then paying a tech to fly across the country to help.

Another thing to remember is that machine mass is critical when trying to get the best finish cuts, specifically in hardwoods.

Ask lots of questions and take pictures when you can. It is always hard to remember what you see in a whirlwind tour.

Know what software you are leaning toward. The style of use is flavored by the software available.

We do very little custom cabinet part nesting with our router because the cabinet guys don't want to use a software like Cab Vision or Cabware. Without one of these tools, nesting custom cabinets is slower than just cutting parts with a saw (including programming, nesting, sourcing material, setup, cutting the part, returning excess material, etc.).

We use the router for standard parts and let the box cutter do the rest.

Obviously, if you are in store fixtures doing multiples or doing apartment cabinets, then this is different (because of the assumed larger quantity of repeating pieces), yet another illustration of how your business mix impacts a purchasing decision.

Do yourself a favor and spend lots of time working through this process; don't let yourself be rushed.

From contributor C:
There is a lot of good advice in this thread. Of course your budget is going to help you focus on what machines you can consider as well as your product line. Are you primarily routing? Do you do large production runs of the same part? You may want to consider a 4 or 6 head CNC like a Heian, Shoda, or Komo with adjustable spindles and tool changers.

If you want to do a lot of horizontal and vertical drilling without large runs, a point-to-point machine with a router would be your best bet.

Keep in mind if you get a multi-head router, you can buy accessories that will enable you to drill horizontal and vertical holes. You can even order a grooving saw.

I agree that a local or independent technician is also a good option when it comes to maintaining your equipment. This is normally more cost-effective due to hourly rates, travel time, and parts. Independents will outsource the parts that they can rather than selling you parts supplied from the manufacturer that are marked up several times before they reach you. Good luck in your CNC purchase.

From the original questioner:
I appreciate the feedback. We are a custom shop but most of what we do will be casework. Currently we use Cabinetware. We have a Holzma panel saw we use for cutting cabinet parts after using the Cabinetware optimizer. I am told by one of the salesman that we will use the saw a lot less and that the nesting function of the router will become our obvious choice for speed and efficiency. We have a budget of $100,000 give or take what is needed. One of my concerns is the ability to master the software. I understand Cabinetware pretty well - I have been using it for several years - but I am a bit fearful of the time commitment required to learn CAD. Is this a big deal? Does one type of system have easier to use CAD or are they all about the same?

From contributor K:
When looking at the different machines and software, I would recommend seeing your parts cut at a local distribution or technology center. Many of the manufacturers and distributors should be set up to show you, start to finish, how to design and cut your parts. If you were going to buy a new car today, you would drive it. I would recommend the same when looking at CNC machinery.

Depending on what you are planning to do, you should still be able to use your Cabinetware to run the machine. As far as learning CAD, some packages are easier then others. Once again, I would look at a package that will give you the best training and support. Someone that is local to you. As far as the time goes, we (Multicam) generally spend two to three days training on the CAD / CAM software and we find that is enough to get people going and using it. You will have a number of questions in the first month.

If you are properly using the CNC router in your manufacturing, most likely you will use your saw less.

From contributor T:
Out of curiosity, why are you looking at nested-based machines in lieu of point to point, if you already have a saw?

From contributor J:
I agree; if you already have a panel saw and software in place to run it, why go nested base? I would look more at a point to point machine to complement the machinery you already have.

We run a Komo VR510 in our small shop in the nested base format, but we are small. It offers flexibility for a low to medium output shop. We don't have a need for the speed with which a panel saw can produce square, sized panels, and therefore save time by cutting and boring on the same machine. We know another shop locally that is in a similar situation to what I suspect you're in. They also bought a Komo like ours about a year and a half ago, and I don't understand why. How many sheets can you stack for cutting in your saw? With a CNC the answer is only one at a time. The cycle time per panel produced is much faster with a panel saw, and a dedicated point to point machining center is much faster at drilling vs. a nested base router with a gang drill pasted onto it. Also, if you have to end-drill any panels, the nested base machine is not going to help much, since you can't get at the edges of your panels without refixturing.

In our shop, the Komo router fits the bill perfectly, but I think in your situation, the actual application of the machine to your production should be explored further. A nested base CNC router is not the magical answer to every shop's problems, but rather the perfect solution to certain shop's production needs.

From contributor F:
Ask for a lengthy list of their customers (CNC vendors you are looking at) doing much the same work as you. Ask them the questions you would normally ask the sales rep, but be more candid.

If you like what you hear from them, sit down with the salesperson. You will likely be in a much better position to garner the information you need to take the next step.

From the original questioner:
I was leaning towards the CNC router primarily because of my understanding as to its flexibility. From my very limited knowledge of the CNC/PTP comparison, the CNC can do what the PTP can do and then some. We can stack 3.5" high on our panel saw but typically do not unless we are doing a production run of store fixtures or the like. A typical job may take 15 sheets of plywood spread out over 10 cutting pages (using the CAbnetware optimizer program). Why wouldn't I get a router for its versatility?

From contributor J:
As I was saying, I don't see a router as a replacement for an existing panel saw, mainly based on speed. As an additional machine for improving flexibility on smaller runs, I couldn't recommend anything else. That's why I was wondering what your volume typically is. It seems like a very logical direction for you.

From contributor C:
You expressed concern regarding the time commitment to use CAD. Good news - you're already using Cabnetware, which is your CAD function. Equally good is you have and are using an optimizer with your Holzma. You basically have what I started with, although my saw is a Mayer. I chose to go with a pod based machine because many of my parts (50%) don't even go to the CNC. So our process goes as follows:

1 - Design the job with CABNETWARE.
2 - Run a CNC link for the job (this creates drilling and routing patterns only, DXF files, and assigns tools).
3 - Export the DXF files to CADCODE (this software, with few steps, creates the machine code which is sent to our Busellato, optimizes the panels and creates label files which are sent to the Mayer panel saw).

At this point all the information has been sent to both the saw and CNC, and a job number is assigned for each material. Now it is time to make the parts. The process goes as follows:

1 - Saw operator pulls up job number and cuts parts. As each part is cut a label is produced and put on the part.
2 - When all parts are cut, they are edgebanded according to the picture on the label. This is very important as it also serves as a visual reference for part orientation on the CNC (PTP).
3 - Labels with a barcode (very important) are scanned at the Busellato and machined.

This outlines our process using a "cut-band-machine" type approach. A few other points I might add:

1 - Make sure your saw (depending on age) will work with the software and produce labels.
2 - Cabnetware's optimizer is not too good (I have it, but cut my losses and use CadCode).
3 - Don't try and set up Cabnetware's CNC link yourself - hire a Cabnetware installer - it's well worth the money. (We were up and running in 3 days from the point you are at now!)

4 - Network your machines together. Don't run around with floppy discs.
5 - Contact the folks at CadCode - they wrote the book on this stuff. If you're lucky enough to speak with Ned Brown, listen to what he tells you!

From contributor S:
Make sure you get a controller that runs with a standard computer. GE Fanac makes one. The controller and computer are in one case by my machine and there is something wrong with my computer. The machine has been down 3 weeks and the bill is up to $7000, and it is still not fixed. For that price I could have bought 7 standard computers. A replacement PCU card alone cost $3000.

From contributor Y:
Take a look at the machining centers with a flat table that can be run in conjunction with your saw by adding pods or possibly a bench and pod machine with a flat table conversion. Flexibility of a router with the capabilities of a PTP also.